Tobacco and process of treating same



Patented Apr. 19, 1938 UNITED STATES PATENT OFFICE Raymond P. Allen, Akron, Ohio No Drawing. Application May 15, 1936, Serial No. 79,917

8 Claims.

The present invention relates to a new and improved process for the treatment of tobacco and the resultant product, it being the purpose of the invention to incorporate with the tobacco substances which are treated or prepared so as to improve the flavor of the tobacco when it is consumed.

The process consists in the addition to the tobacco of a highly activated adsorbent material upon which the tobacco conditioning material has been adsorbed and by which it is retained until released during smoking by the heat of combustion.

The present invention is disclosed and discussed in my copending application Serial No. 648,439,

filed December 22, 1932, now patent No. 2,063,014, dated Dec. 8, 1936, said application, however, being specifically directed to the use of menthol or other aromatic or volatile flavoring material held by the adsorbent and released upon the elevation of the temperature during smoking. This application is a continuation-in-part of the subject matter disclosed in said earlier application, but is directed particularly to the use of moisture as the tobacco conditioning agent which is held by the adsorbent.

The process, and product which results therefrom, which is desired to be covered in the present application, consists in the mixture with tobacco of silica hydrogel or other strongly adsorbent material which has been highly activated so that it will retain moisture indefinitely and will release it only as the combustion of the tobacco raises the temperature to a degree at which the moisture is released. The importance of using a highly activated adsorbent is apparent when it is realized that the object and effect of the invention is to retain the moisture indefinitely within the tobacco, so that, although the tobacco itself may be dried out, as the point of combustion advances the moisture held upon the adsorbent is released and imparted to the tobacco at the burning point. The moisture thus released passes into the tobacco and immediately restores it to the full flavor and aroma, so that when the tobacco is smoked the taste and aroma are the same as freshly prepared tobacco.

It will be seen that the invention is an important advance in the tobacco art as it makes unnecessary elaborate precautions which are now taken to retain the requisite amount of moisture in the tobacco after manufacture of the tobacco products. For example, it is the practice to Wrap packets of cigarettes with moisture-proof coverings or jackets to retain the original moisture content, but such precautions do not always work satisfactorily and after a pack of cigarettes is opened they will lose their moisture rapidly, particularly in a dry atmosphere. The flavor and aroma of tobacco depends to a considerable extent upon the amount of moisture present, and dry tobacco is harsh, flavorless and irritating, but

as the process outlined herein will restore the lost moisture to the tobacco as it is smoked, the elaborate precautions which are now taken to retain 10 the evanescent moisture may be eliminated.

Tobacco which has been treated by the process herein described will retain the essential moisture indefinitely. This is true even though the tobacco is stored under conditions of temperature, pressure and humidity which are distinctly unfavorable for the retention of moisture in tobacco as ordinarily prepared. This is due to the fact that with highly activated adsorbents such as are intended to be employed, the vapor pressure of the adsorbed moisture is so low that it will be retained until released by the advancing burning area of the cigarette, cigar or pipe tobacco.

The inventor does not propose nor does he desire to denature the tobacco or the tobacco smoke. Tobacco treated by the process will not lose any of its flavor, nor will the smoke be deprived of any of its desirable physiological effects. It is not believed that tobacco is by any means as harmful or unpleasant as remarked by a number of workers in the prior art who have sought to use an adsorbent as a means of depriving tobacco smoke of its organic constituents, such as aromatic substances and the alkaloids, which, in reality, give the flavor and kick to smoking. What the inventor proposes to do is to have within the tobacco relatively small amounts of a highly activated adsorbent which has been previously treated with water to such an extent that the adsorbent will not intercept or adsorb any substantial quantity of the smoke ingredients, but, on the contrary, the adsorbent will release to the tobacco an added supply of moisture which will go into the tobacco as it burns.

This conception of using the highly activated adsorbents in a new and difierent manner is not to be confused with the use of the adsorbent as a filter or interceptor of any of the ingredients of the tobacco smoke.

In order to carry out the purposes of the invention to the greatest efiiciency, it is desirable that the adsorbent be most effective and for this purpose it is highly activated before use by approved methods known to those skilled in the 55 use of such materials. For example, silica gel may be activated by heating to a temperature of 300 C. for two hours, whereupon it is capable of adsorbing approximately twenty percent by weight of moisture. The more carefully the activation is carried out, the more tenaciously the moisture will be retained until it is finally released by the combustion of the tobacco.

A small amount of adsorbent treated in this manner is sprinkled or dusted over the loose tobacco before it is made into cigarettes or otherwise prepared for the market. In the manufacture of cigarettes, five percent of the treated adsorbent may be added to the tobacco with excellent results. It is found most desirable to have the adsorbent finely divided, for example, of the order of size of material which will pass a standard sieve with two hundred meshes to the inch, but the invention is not limited to the use of adsorbents of this dimension.

While silica hydrogel has been mentioned, other strongly adsorbent substances may be used. For example, other siliceous substances such as kieselguhr, fullers earth, certain clays and siliceous earth, when properly activated, or carbonaceous material such as activated charcoal, or aluminiferous substances such as activated bauxite and alumina hydrogel, or other strongly adsorbent substances such as properly prepared ferric oxide may be used in place of the silica hydrogel as adsorbing agents for moisture or aromatic substances. An advantage of all of the adsorbent materials mentioned which are used in this process is that they are tasteless and odorless, even when heated. From this standpoint, therefore, they serve as ideal carriers of flavors, while they themselves remain physiologically inert.

No special precautions are ordinarily necessary in order to make the silica gel or other adsorbent material adhere to the tobacco, but the process may in some cases be improved by using a small amount of a physiologically inert adhesive such as a dilute solution of water glass.

It will be understood that the purposes and objects of the invention may be carried out by the use of other adsorbents than those specifically mention-ed, and that exact conformity with detailed steps of the process as outlined are not essential. Silica gel, alumina hydrogel and ferric oxide hydrogel are the preferred adsorbents, but other adsorbents may become available and be found to be more effective. It is not the intention that such materials be excluded.

The invention is one which adds and restores to the tobacco the conditioning agent which, until burning time, has been retained by the adsorbent. In the specific embodiment of the invention herein covered, the conditioning agent is moisture, while the copending application referred to above is directed to the use of other volatile or aromatic conditioning agents.

What is claimed is:

1. A substantially homogeneous mixture of tobacco and a highly activated adsorbent on which has been adsorbed moisture to the extent that the adsorbent is incapable of adsorbing substantial quantities of the organic vapors which are normally present in tobacco smoke, the vapor pressure of the water being suificiently low when adsorbed to be substantially retained within the adsorbent until released as the temperature is raised by the combustion of the tobacco.

2. A substantially homogeneous mixture of tobacco and a highly activated silica gel on which has been adsorbed moisture to the extent that the silica gel is incapable of adsorbing substantial quantities of the organic vapors which are normally present in tobacco smoke, the vapor pressure of the Water being sufiiciently low when adsorbed to be substantially retained within the silica gel until released as the temperature is raised by the combustion of the tobacco.

3. A substantially homogeneous mixture of tobacco and a highly activated alumina hydrogel on which has been adsorbed moisture to the extent that the alumina hydrogel is incapable of adsorbing substantial quantities of the organic vapors which are normally present in tobacco smoke, the vapor pressure of the water being sufliciently low when adsorbed to be substantially retained within the alumina hydrogel until released as the temperature is raised by the combustion of the tobacco.

4. A substantially homogeneous mixture of tobacco and a highly activated ferric oxide hydrogel on which has been adsorbed moisture to the extent that the ferric oxide hydrogel is incapable of adsorbing substantial quantities of the organic vapors which are normally present in tobacco smoke, the vapor pressure of the water being sufiiciently low when adsorbed to be substantially retained within the ferric oxide hydrogel until released as the temperature is raised by the combustion of the tobacco.

5. A process which comprises adsorbing moisture on a highly activated adsorbent to the extent that the adsorbent is incapable of adsorbing substantial quantities of the organic vapors which are normally present in tobacco smoke, and mixing it into smoking tobacco, whereby the adsorbed moisture is substantially retained in the mixture until released as the temperature is raised by the combustion of the tobacco.

6. A process which comprises adsorbing moisture on a highly activated silica gel to the extent that the silica gel is incapable of adsorbing substantial quantities of the organic vapors which are normally present in tobacco smoke, and mixing it into smoking tobacco, whereby the adsorbed moisture is substantially retained in the mixture until released as the temperature is raised by the combustion of the tobacco.

7. A process which comprises adsorbing moisture on a highly activated alumina hydrogel to the extent that the alumina hydrogel is incapable of adsorbing substantial quantities of the organic vapors which are normally present in tobacco smoke, and mixing it into smoking tobacco, whereby the adsorbed moisture is substantially retained in the mixture until released as the temperature is raised by the combustion of the tobacco.

8. A process which comprises adsorbing moisture on a highly activated ferric oxide hydrogel to the extent that the ferric oxide hydrogel is incapable of adsorbing substantial quantities of the organic vapors which are normally present in tobacco smoke, and mixing it into smoking tobacco, whereby the adsorbed moisture is substantially retained in the mixture until released as the temperature is raised by the combustion of the tobacco.

RAYMQN P. ALLEN. 

